1. Field of the Invention
This invention relates to beverage dispensers of the type adapted to be carried on the back of a vendor.
Portable beverage dispensers are generally well known including those adapted to be transported on the back of a vendor by use of a body harness as disclosed by way of example in U.S. Pat. No. 2,684,787 to Charpiat and U.S. Pat. No. 2,808,965 to Grafia et al. Such portable beverage dispensers include a tank made of rigid material enclosing a liquid storing chamber from which the beverage is dispensed and into which the beverage is charged through a reloading valve connected to the bottom of the tank. The beverage is accordingly dispensed under a gravitational pressure head. As an obvious expendient to assist in dispensing of the beverage, particularly when the liquid within the tank becomes depleted, the tank chamber may be internally pressurized with air by means of a pump as disclosed for example in U.S. Pat. No. 3,147,889 to Dolgin. The use of a hand operated piston pump on top of the tank for such purpose was also associated with a commercially available beverage dispenser in publich use for several years, marketed by Brute Enterprises of Houston, Tex. Fluid dispensers that are internally pressurized through a flexible bladder are also known, as disclosed in U.S. Pat. No. 2,513,455 to Cornelius.
It will be apparent that the aforementioned types of prior art beverage dispensers are limited in liquid volume capacity consistent with the dimensional and weight limitations associated with transport of the dispenser by a human vendor. One major factor associated with portable dispensers utilizing a rigid tank is its ability to be internally pressurized without expansion. The strength requirement for the tank is therefore increased so as to require a corresponding increase in material thickness. Further, internal pressurization promotes deterioration of internal tank surfaces so as to limit tank construction to expensive materials such as stainless steel as a practical matter. Also, the internal pressurization of the tank heretofore caused some degradation in the quality of the beverage, such as loss of the carbonation.
It is therefore an important object of the present invention to provide a portable beverage dispenser of the rigid tank type within which the liquid beverage is pressurized to enhance dispensing thereof without the disadvantages aforementioned in connection with the prior art.
An additional object of the present invention in accordance with the foregoing object is to provide a portable beverage dispenser capable of being constructed with lighter materials and reduced thickness, and capable of being more readily serviced and repaired as compared to prior art arrangements.
Yet another object of the present invention is to provide the aforementioned type of rigid tank beverage dispenser that is internally pressurized with air without any adverse effect on the quality of the beverage dispensed. For example, carbonated beverages may be dispensed without loss of carbonation and without any need to inject carbon dioxide into the tank.